Removed obsolete link setter that caused bugs.

prs.classes/Entities/PurchaseOrder/PurchaseOrderItem.cs

@@ -148,7 +148,7 @@ namespace Comal.Classes
         public ProductLink ProductLink
         {
             get { return Product; }
-            set { Product = value; }
+            set { /* We cannot set the 'Product' to this value, because that would stuff the SubObject internal linking, so we do nothing instead. */ }
         }
         
         [EntityRelationship(DeleteAction.SetNull)]
@@ -157,7 +157,7 @@ namespace Comal.Classes
         public ProductStyleLink StyleLink
         {
             get { return Style; }
-            set { Style = value; }
+            set { /* Same as ProductLink */ }
         }